PFS FUELTEC · HOW IT WORKS

How DL pressure leak detection works

Underground double-skin tanks · SGB DL range · PFS standard models: DL 280 and DL 330

1Step 1 of 6 · Normal operation

Air pressure watches both walls

The space between the two steel walls is pressurised. With both walls intact, the pressure stays above the alarm threshold.

Look at the highlighted ring between the walls.

More detail

Double-skin underground steel tankBoth tank walls are intact. The highlighted space between them contains pressurised air. Ground level FuelVapour space Air Supply Line from Leak DetectorPressure monitoring lineto Leak Detector Air-filledinterstice Outer wallInner wallBoth walls intact 1
Tank cross-section · wall gap enlarged for clarity
SGB DLEXPLANATORY SCHEMATIC
Power onNo alarm
Interstitial pressureAt Pump OFF
Illustrative spacing; switching pressures depend on model.
Internal pump: stoppedPump OFF pressure reached
Pump illustration only — no pump-on indicator lamp.
Alarm relay → external device
1112
Contact closedVoltage-free alarm contact
BMS / alarm panelAlarm input normal

When wired to a compatible external device, the relay passes on the alarm.

About this demonstration

Select Next when you are ready. Nothing advances automatically. This example assumes a correctly specified system and a leak that exceeds pump capacity. Slow normal decay and quick top-up are shown at illustrative speeds; actual cycle times depend on the installation. The illustrated relay contact opens on alarm or loss of power; external equipment needs a suitable input and its own supply. The detector reports pressure loss; it does not identify which wall or location has breached. No audio is played.